Chem 103 Lab Exam 4 Review

Chem 103 Lab Exam 4 Review Question 1 10 / 10 pts 1. (3 points) What does it mean that the heat of a reaction is an extensive property? 2. (3 points) Does the following reaction give off heat or absorb heat? Explain briefly. C D H = +263Kcal/mol 3. (4 points) In one experiment in the video, room temperature water was mixed with water at about 38 degrees. To what temperature (about) did the mixture of the two water samples come to after setting for a few minutes? Your Answer: 1. Extensive properties can be mass or volume, depend on the amount of matter being measured 2. Endothermic absorbs heat because delta H Positive 3. 29.8 C 1. The heat depends on the amount of substance. If the amount of substance is doubled, then the heat doubles. Other properties, such as density, are intensive, which means the amount of substance does not matter. 2. The (+) value indicates this reaction absorbs heat. 3. The mixture reached 30oC, but settled to 29.8oC.